| // -- control_structures.cpp -- The Boost Lambda Library ------------------ |
| // |
| // Copyright (C) 2000-2003 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi) |
| // Copyright (C) 2000-2003 Gary Powell (powellg@amazon.com) |
| // |
| // Distributed under the Boost Software License, Version 1.0. (See |
| // accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| // |
| // For more information, see www.boost.org |
| |
| // ----------------------------------------------------------------------- |
| |
| #include <boost/test/minimal.hpp> // see "Header Implementation Option" |
| |
| #include "boost/lambda/lambda.hpp" |
| #include "boost/lambda/if.hpp" |
| #include "boost/lambda/loops.hpp" |
| |
| #include <iostream> |
| #include <algorithm> |
| #include <vector> |
| |
| using namespace boost; |
| |
| using boost::lambda::constant; |
| using boost::lambda::_1; |
| using boost::lambda::_2; |
| using boost::lambda::_3; |
| using boost::lambda::make_const; |
| using boost::lambda::for_loop; |
| using boost::lambda::while_loop; |
| using boost::lambda::do_while_loop; |
| using boost::lambda::if_then; |
| using boost::lambda::if_then_else; |
| using boost::lambda::if_then_else_return; |
| |
| // 2 container for_each |
| template <class InputIter1, class InputIter2, class Function> |
| Function for_each(InputIter1 first, InputIter1 last, |
| InputIter2 first2, Function f) { |
| for ( ; first != last; ++first, ++first2) |
| f(*first, *first2); |
| return f; |
| } |
| |
| void simple_loops() { |
| |
| // for loops --------------------------------------------------------- |
| int i; |
| int arithmetic_series = 0; |
| for_loop(_1 = 0, _1 < 10, _1++, arithmetic_series += _1)(i); |
| BOOST_CHECK(arithmetic_series == 45); |
| |
| // no body case |
| for_loop(boost::lambda::var(i) = 0, boost::lambda::var(i) < 100, ++boost::lambda::var(i))(); |
| BOOST_CHECK(i == 100); |
| |
| // while loops ------------------------------------------------------- |
| int a = 0, b = 0, c = 0; |
| |
| while_loop((_1 + _2) >= (_1 * _2), (++_1, ++_2, ++_3))(a, b, c); |
| BOOST_CHECK(c == 3); |
| |
| int count; |
| count = 0; i = 0; |
| while_loop(_1++ < 10, ++boost::lambda::var(count))(i); |
| BOOST_CHECK(count == 10); |
| |
| // note that the first parameter of do_while_loop is the condition |
| count = 0; i = 0; |
| do_while_loop(_1++ < 10, ++boost::lambda::var(count))(i); |
| BOOST_CHECK(count == 11); |
| |
| a = 0; |
| do_while_loop(constant(false), _1++)(a); |
| BOOST_CHECK(a == 1); |
| |
| // no body cases |
| a = 40; b = 30; |
| while_loop(--_1 > _2)(a, b); |
| BOOST_CHECK(a == b); |
| |
| // (the no body case for do_while_loop is pretty redundant) |
| a = 40; b = 30; |
| do_while_loop(--_1 > _2)(a, b); |
| BOOST_CHECK(a == b); |
| |
| |
| } |
| |
| void simple_ifs () { |
| |
| int value = 42; |
| if_then(_1 < 0, _1 = 0)(value); |
| BOOST_CHECK(value == 42); |
| |
| value = -42; |
| if_then(_1 < 0, _1 = -_1)(value); |
| BOOST_CHECK(value == 42); |
| |
| int min; |
| if_then_else(_1 < _2, boost::lambda::var(min) = _1, boost::lambda::var(min) = _2) |
| (make_const(1), make_const(2)); |
| BOOST_CHECK(min == 1); |
| |
| if_then_else(_1 < _2, boost::lambda::var(min) = _1, boost::lambda::var(min) = _2) |
| (make_const(5), make_const(3)); |
| BOOST_CHECK(min == 3); |
| |
| int x, y; |
| x = -1; y = 1; |
| BOOST_CHECK(if_then_else_return(_1 < _2, _2, _1)(x, y) == (std::max)(x ,y)); |
| BOOST_CHECK(if_then_else_return(_1 < _2, _2, _1)(y, x) == (std::max)(x ,y)); |
| } |
| |
| |
| int test_main(int, char *[]) |
| { |
| simple_loops(); |
| simple_ifs(); |
| return 0; |
| } |